1. Field of the Invention
The present invention relates to digital visual interface connector technology and more particularly, to a digital visual interface dual-stack connector, which accurately achieves impedance matching to reduce high frequency signal reflection by means of controlling the bending angles of curved portions of the second terminal pins of the second connector thereof and the pitch between each two adjacent second terminal pins, enhancing signal transmission stability and reliability.
2. Description of the Related Art
Today's transmission technology has entered the digital era. Users and manufacturers have become increasingly demanding in the quality of digital display. The ongoing progress of display card hardware-combined digital display interface standards attracts much people's attention. High speed transmission technology keeps improving to satisfy digital audio and video transmission requirements. Digital Visual Interface (DVI) is a video display interface developed by the Digital Display Working Group (DDWG). The digital interface is used to connect a video source to a display device, such as a computer monitor. DVI was developed to create an industry standard for the transfer of digital video content.
The interface is designed to transmit uncompressed digital video and can be configured to support multiple modes such as DVI-D (digital only), DVI-A (analog only), or DVI-I (digital and analog). Featuring support for analog connections as well, the DVI specification provides optional compatibility with the VGA interface. This compatibility along with other advantages led to widespread acceptance in the PC industry over other competing digital standards. Though predominantly found in computer devices, DVI is also present in some consumer electronics such as LCD, digital projector, DVD player, set-top box, D-VHS player, video receiver and other consumer electronic products sets. DVI connectors are intensively used in different electronic products for connection to a notebook computer or the panel of a LCD TV or display means. The DVI connector usually contains pins to pass the DVI-native digital video signals. In the case of dual link systems, additional pins provide increased bandwidth allowing higher resolutions and longer distances. The DVI connector includes three types: DVI-D (digital only, single-link or dual-link), DVI-A (analog only), DVI-I (integrated, combines digital and analog in the same connector; digital may be single- or dual-link). Further, commercial DVI connectors are generally of a single layer design, not able to satisfy high bandwidth and multi-display transmission requirements. In order to eliminate the problem of port occupation by multiple display cards and to facilitate wiring arrangement, DVI dual-stack connectors are created. A DVI dual-stack connector provides multiple signal transmission channels to satisfy high bandwidth and multi-display transmission requirements. However, the designs of commercial DVI dual-stack connectors do not consider the factors of high frequency signal transmission characteristics (such as electromagnetic interference, impedance matching), i.e., prior art DVI dual-stack connectors cannot achieve perfect impedance matching to reduce high frequency signal reflection, leading to poor signal transmission stability and reliability.